生活垃圾分类投放点挥发性有机物的释放特征及大气化学反应活性

Characteristic and Chemical Reactivity of Volatile Organic Compounds in Emissions from a Collection Site for Separated Municipal SolidWaste

选取上海市某小区为研究区域,采集生活垃圾分类投放点干湿垃圾桶中气体样品,检测其中的VOCs组成和浓度,同时从反应活性角度估算其臭氧生成潜力(ozone formation potential,OFP)和二次有机气溶胶生成潜势(secondary organic aerosol formation potential,SOAFP)。研究结果表明,不同季节湿垃圾桶中检测到的VOCs浓度(58.30∼3322µg/m^(3))均高于干垃圾桶(21.70∼1671µg/m^(3))。其中,夏季检测到的VOCs浓度均比其他3个季节高出1∼2个数量级。干湿垃圾中均以含氧化合物和卤代化合物为主。OFP和SOAFP均具有明显季节变化特征,干湿垃圾桶均在夏季OFP较大,其中夏季乙醇是促进臭氧生成的优势物质,其他季节为苯乙烯、丙烯、间/对二甲苯和甲苯;干垃圾桶在夏季SOAFP最大,湿垃圾桶在冬季SOAFP最大,且以甲苯、苯乙烯、间/对二甲苯和苯为主的芳香化合物是SOAFP的主要物种。

In this paper,a residential area in Shanghai was selected as the research area,and gas samples were collected from dry and wet garbage cans at a collection site for separated municipal solid waste.The composition and concentration of VOCs were detected,and the ozone formation potential(OFP)and secondary organic aerosol formation potential(SOAFP)were estimated from the perspective of reactivity.The results showed that the concentration of VOCs in wet garbage cans(58.30-3322µg/m^(3))was higher than that in dry garbage cans(21.70-1671µg/m^(3))in different seasons.The concentration of VOCs detected in summer was 1-2 orders of magnitude higher than that in the other three seasons.Both dry and wet wastes were dominated by oxygen-containing compounds and halogenated compounds.Both OFP and SOAFP had obvious seasonal variation characteristics.The OFP of both dry and wet garbage cans was higher in summer.In summer,ethanol was the dominant substance to promote ozone generation,while in other seasons,styrene,propylene,m-,p-xylene and toluene were the dominant substances.The SOAFP of dry garbage cans was the largest in summer,and the SOAFP of wet garbage cans was the largest in winter.The aromatic compounds mainly composed of toluene,styrene,m-,p-xylene and benzene were the main species of SOAFP.